System and method for warning of potential collisions

ABSTRACT

A collision avoidance system for a vehicle. The collision avoidance system includes one or more transmitting devices, one or more receiving devices, a control module and a mirror. The receiving devices receive return signals and send information regarding the return signals to the control module. The control module detects a hazard based on the information received from one or more receiving devices. The mirror includes visual indicators for warning a driver of the hazard detected by the control module.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.09/621,748, filed Jul. 21, 2000, which claimed priority under 35 U.S.C.119(e) of U.S. Provisional Application Ser. No. 60/145,156, filed Jul.22, 1999, which applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to sensor-based systems, andmore particularly to a vehicle-mounted collision avoidance system whichwarns drivers of potential collisions.

2. Background Information

The roads are becoming more and more congested with vehicular traffic.As traffic congestion has increased, the number of accidents has alsoincreased. Some of these accidents can be traced to driverinattentiveness or to the failure of the driver or of other drivers tosee and react to surrounding vehicles.

Muth Mirror Systems of Sheboygan, Wis. manufactures a side view mirrorwith a built-in turn signal display (a “chevron”). The side view mirrorcan be mounted on both the passenger and driver sides of the vehicle andincludes light emitting diodes (LEDs) which blink in time to the turnsignal. The chevron is designed to be clearly visible to drivers in thelane adjacent to the host vehicle.

Such a display is good for warning drivers of adjacent vehicles. It doeslittle, however, to warn the driver of the host vehicle of potentialcollisions.

Systems for warning drivers of objects external to their vehicle havebeen around for a long time. Mirrors, and sometimes combinations ofmirrors, are being used to reveal locations hidden to the driver's view(i.e. “blind spots”). Mirrors, however, have a deficiency in that thedriver can only look in one spot at any one time, and no one mirror canprovide a complete view of all the possible blind spots. If they look inone mirror, see that the way is clear, start looking elsewhere and thena vehicle pulls into the area they thought was clear, they won't see itand may run into the vehicle. For example, if the driver looks at thelane adjacent to the vehicle, sees that the way is clear, starts lookingelsewhere and then a vehicle pulls along side, the driver won't see itand may clip the vehicle while changing lanes.

In addition, mirrors don't work well in changing lanes, particularly intractor-trailer rigs. One reason is that a side view mirror only looksin the lane adjacent to the vehicle and to the rear of the side viewmirror. Vehicles forward of the side view mirror or more than one laneaway from the vehicle may be missed. In addition, as soon as the rigbegins to turn, the mirror that looked down along the side of thevehicle is directed into the side of the trailer and the driver isblinded to activity on that side of his truck.

Sensor-based warning systems have also been proposed. For instance,Sonar Safety Systems of Santa Fe Springs, Calif. has a rear-mountedsensor system based on a single sensor which detects objects in threedistance zones from the rear of the vehicle. The system provides alarmsand audible feedback that inform the driver whether the obstacle isclose (Zone III), out a little farther (Zone II), or even farther outyet (Zone I).

What is needed is a system and method for automatically warning thedriver of potential collisions at the front, to the sides and behind avehicle.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a collision avoidancesystem for a vehicle includes one or more transmitting devices, one ormore receiving devices, a control module and a mirror. The receivingdevices receive return signals and send information regarding the returnsignals to the control module. The control module detects a hazard basedon the information received from the one or more receiving devices. Themirror includes visual indicators for warning a driver of the hazarddetected by the control module.

According to another aspect of the present invention, a method ofalerting a driver of potential hazards is described. A potentialcollision event is detected and a symbol is displayed within a mirrorindicating that the potential collision event has been detected.

According to yet another aspect of the present invention, a collisionavoidance system includes a plurality of transmitting devices, aplurality of receiving devices, a control module connected to theplurality of transmitting devices and the plurality of receiving devicesand a side view mirror. The plurality of transmitting devices include afirst and a second transmitting device, wherein the first and secondtransmitting devices transmit a first signal and a second signal,respectively. The plurality of receiving devices include a first and asecond receiving device, wherein the first receiving device receives areturn representative of the signal transmitted from the firsttransmitting device and transmits a first return signal representativeof the first return and wherein the second receiving device receives areturn of the signal transmitted from the second transmitting device anda second return signal representative of the return. The control modulereceives the first and second return signals and detects potentialhazards as a function of the first and second control signals. The sideview mirror includes visual indicators for warning a driver of potentialhazards detected by the control module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a collision avoidance system;

FIG. 2 shows a more complex embodiment of the collision avoidance systemshown in FIG. 1;

FIG. 3 is a system block diagram of a collision avoidance systemaccording to FIG. 2;

FIGS. 4 a and 4 b show side view mirror displays which can be used withthe control modules of FIGS. 1 and 3;

FIGS. 5 a-c show the operation of two rear-mounted sensors according tothe present invention;

FIGS. 6 a-c show one embodiment of an operator interface units which canbe used with the control modules of FIGS. 1 and 3;

FIG. 7 illustrates a backup warning system;

FIGS. 8 and 9 show wireless portable transducer systems;

FIG. 10 illustrates a side display module;

FIG. 11 illustrates an alternate embodiment of a collision avoidancesystem;

FIG. 12 illustrates a mirror-mounted display; and

FIGS. 13 and 14 illustrate a side-mounted display.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which is shown by way of illustration specific embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from the scope of the present invention.

Some portions of the detailed descriptions which follow are presented interms of algorithms and symbolic representations of operations on databits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of steps leading to a desiredresult. The steps are those requiring physical manipulations of physicalquantities. Usually, though not necessarily, these quantities take theform of electrical or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like. It should be borne in mind, however, thatall of these and similar terms are to be associated with the appropriatephysical quantities and are merely convenient labels applied to thesequantities. Unless specifically stated otherwise as apparent from thefollowing discussions, terms such as “processing” or “computing” or“calculating” or “determining” or “displaying” or the like, refer to theaction and processes of a computer system, or similar computing device,that manipulates and transforms data represented as physical (e.g.,electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

FIG. 1 shows a collision avoidance system 10 according to the presentinvention. System 10 includes a control module 12 and two sensors 14.Each sensor 14 includes a transmitter 16 and a receiver 18. In oneembodiment, transmitter 16 and receiver 18 are mounted together in asingle sensor housing. In another embodiment, transmitter 16 andreceiver 18 are mounted in separate housings.

In one embodiment, sensors 14 include separate acoustic transducers foreach of transmitter 16 and receiver 18. In another embodiment, a singleacoustic transducer is used for both transmitting a signal and receivingits echo. Some transducers which would operate in such a system 10 arethe 9000 Series Piezo Transducers available from Polaroid OEM ComponentsGroup and the KSN 6530 45 KHz transducer available from Motorola. Inaddition, the KSN 6529 45 KHz transducer available from Motorola couldbe used for receiver 18.

In another embodiment, sensors 14 are micropower impulse radar (MIR)devices. In one embodiment, MIR devices such as those described in thewhite paper entitled “Microwave Impulse Radar (MIR) TechnologyOverview”, available from Lawrence Livermore National Laboratory, areused. The advantage of such devices are that they are low power andfairly inexpensive. In addition, a single device can be used as bothtransmitter 16 and receiver 18.

In yet another embodiment, sensors 14 are microwave or millimeter wavetransceiver devices. In one such embodiment, each transceiver includes asmall integrated antenna and electronic interface board. In anotherembodiment, sensors 14 include both proximity detectors 14.1 and longerrange detectors 14.2. The longer range detectors incorporate a largerantenna to operate as a Doppler Radar Forward Looking Detector. Anexample of one such transducer is the model DRO3000 MicrowaveTransceiver Module available from Advanced Frequency Products ofAndover, Mass.

In one embodiment, such as is shown in FIG. 2, a collision avoidancesystem 30 includes up to seventeen sensors 14 mounted around theperiphery of a vehicle.

A variety of collision avoidance systems are described in “System andMethod of Avoiding Collisions,” U.S. patent application Ser. No.09/130,279, filed Aug. 6, 1998 and assigned to the assignee of thepresent invention, the descriptions of which are hereby incorporated byreference.

In one embodiment, sensors 14 of system 30 are grouped in detectorsubsystems. The output from each detector subsystem is fed into controlmodule 12, as is shown in FIG. 3. As shown in FIG. 3, system 30 includesa control module 12, an operator interface 32, a proximity detectorsubsystem 34 and a rear guard subsystem 36. Each subsystem includes oneor more sensors 14. System 30 may also include a forward-lookingdetector subsystem 33 (with two or more sensors).

In one embodiment, each sensor 14 is a stand alone smart sensor as isdescribed in “System and Method of Providing Scalable Sensor SystemsBased on Stand Alone Sensor Modules,” U.S. patent application Ser. No.09/505,418, filed Feb. 16, 2000 and assigned to the present assignee.The description of the sensors and of systems of such sensors isincorporated herein by reference.

In one embodiment, proximity detector subsystem 34 includes up to 15sensors and rear-guard subsystem 36 includes up to 7 sensors. The outputof each sensor in each detection subsystem is fed into control module12, as shown in FIG. 3.

In one embodiment, system 30 includes side displays 35, side warninglights 37 and rear warning lights 39. In one embodiment, control module12 includes a vehicle inputs module 38 for receiving signals from othervehicle sensors. In addition, control module 12 may communicate with anon-board computer 31.

In one embodiment, side displays 35 and side warning lights 37 areintegrated into the side view mirror of the vehicle. One such embodimentis shown in FIG. 4 a, where a left side view mirror 40 includes achevron 42, a slash 44 and a backup indicator 46. A similar embodimentis shown in FIG. 4 b, where right side view mirror 41 includes a chevron42, a slash 44 and a backup indicator 46. A numeric range indicator,such as indicator 35 shown in FIG. 10 could also be included.

Chevron 42 is a arrow-shaped set of LEDs which flash in time to the turnsignal. The arrow-shaped chevron is visible by drivers of vehicles inthe adjacent lane as a warning to them that the host vehicle is about toturn or change lanes. In another embodiment, a flashing amber light orother such visual warning can be directed at vehicles in adjacent lanes.

Slash 44 is a diagonal line of LEDs which flash to indicate that thereis a potential hazard in the adjacent lane which would make a lanechange or turn unwise. For example, if the left turn signal is activatedindicating the driver's intent to change lanes to the left, or to make aleft turn, slash 44 will flash in side view mirror 40 if an object isdetected within a specified range of the left side of the vehicle. Thesame is true for the right side mirror if the right turn signal isactive and an object is detected on the right hand side of the vehicle.

In one embodiment, slash 44 is a diagonal series of LEDs that crossmirrors 40 and 41 between two opposite corners. A more reduced line ofLEDs could also be used.

In one embodiment, slash 44 is a steady-state indicator which remains onas long as the turn signal is on and the potential hazard is detected.In another embodiment, slash 44 pulses on and off at a rate of 4 Hz tocatch the driver's attention. Other flashing sequences could also beused.

Backup indicator 46 is a series of LED symbols used to help the driveravoid objects while backing up the vehicle. In one embodiment, the LEDsare arranged in a horizontal row along the top or bottom of each sideview mirror. In one embodiment, backup indicator 46 is incorporated inonly one of the side view mirrors 40 or 41.

In one embodiment, triangle 48 is displayed when the transmission is inreverse and an object is detected within a predefined distance (e.g., 25feet) of the rear of the vehicle. In one such embodiment, triangle 48 isa cluster of three LEDs such as is shown in FIGS. 4 a and 4 b.

In one embodiment both triangle 48 and the remaining four LEDs aredisplayed when the transmission is in reverse and an object is detectedwithin a predefined distance (e.g., 25 feet) of the rear of the vehicle.In one such embodiment, the four LEDs are turned off one at a timemoving closer to triangle 48 as the vehicle moves closer to the objectbehind the truck. When the vehicle is at close range to the objectbehind the truck, the four LEDs and the triangle flash (e.g., at 4 Hz)to alert the driver to stop the vehicle.

In one embodiment, the remaining four LEDs turn on one at a time movingcloser to the triangle as the vehicle moves closer to the object behindthe truck. When the truck is within a second predefined distance (e.g.,three feet) of the object, all four LEDs flash (e.g., at 4 Hz) to alertthe driver to stop the vehicle. The LEDs remain flashing until thetransmission is shifted out of reverse.

In another embodiment, the LED furthest from triangle 48 (LED 4) lightswhen the distance is less than 25 feet but greater than 12 feet. Thenext LED (LED 3) lights when the distance is less than 25 feet butgreater than 8 feet. The next LED (LED 2) lights when the distance isless than 25 feet but greater than 5 feet and the final LED (LED 1)lights when the distance is less than 25 feet but greater than 3 feet.As in above, when the truck is within 3 feet of the object, all fourLEDs flash to alert the driver to stop the vehicle, and remain flashinguntil the transmission is shifted out of reverse.

An alternative to the sequencing of LEDs 46 described above is toincorporate a numeric range indicator 35 such as is shown in FIG. 10.

Such an approach integrates a lot of information into the side viewmirrors. Since the side view mirrors have to be viewed as part of aturn, lane change or when backing the vehicle, such an approach providesa lot of information with minimal impact on the driver.

Other symbols can also be used. For example, slash 44 can be replacedwith a different symbol. Also, the triangle and series of LEDs of backupindicator 46 can be replaced with another form of distance-relatedinformation.

In one embodiment, separate nine wire cables run from control module 12to each of side mirrors 40 and 41. Each wire is at least 18-gaugestranded wire. The cables are connected to control module 12 with ninepin D subminiature connectors.

In another embodiment, a two-wire data communication cable is run from astand-alone smart sensor to a display processor in the manner describedin “System and Method of Providing Scalable Sensor Systems Based onStand Alone Sensor Modules,” described above, the description of whichis incorporated herein by reference. The hazard information is sent fromthe stand-alone smart sensor over the data communications cable to thedisplay processor which, in turn, drives the visual indicators in sideview mirrors 40 and 41.

In one embodiment, a digital I/O board within control module 12 drivesLEDs within each of side mirrors 40 and 41. A control register withinthe digital I/O board contains eight left side mirror bits and eightright side mirror bits. In one embodiment, each bit is associated with aparticular function. For instance, in one embodiment, each set of bitsincludes one bit for each of the individual LEDs 1-4 on its respectiveside mirror, a bit for triangle 48 and a bit for slash 44. In addition,a bit can be used to place side mirror 40 in a flash mode whichoverrides the individual bits to place LEDs 1-4 and triangle 48 in aflashing status during which LEDs 1-4 and triangle 48 flash at apredetermined frequency (e.g., 4 Hz).

In another embodiment, control circuitry is placed in proximity tomirrors 40 and 41 and control module 12 writes commands to the controlcircuitry to cause the appropriate signals to light or flash. Such anapproach reduces the amount of wiring needed to put system 30 in place.

In one embodiment, a single bit is used to turn on triangles 48 inmirrors 40 and 41. This reflects the fact that triangles 48 willtypically be active at the same time. Similarly, LEDs 1-4 for both theleft and right side could be driven by the same bits and driverelectronics.

In one embodiment, control module 12 includes program code forinitiating a self test. During self test, all LEDs in side mirrors 40and 41 are lit for a predetermined period (e.g., five seconds) so thatthe driver can verify that all lights are operational. Self test isentered automatically during the system initialization process, or canbe initiated by the driver.

In another embodiment, the LEDs flash on and off for a predeterminedperiod of time during self test.

Collision Avoidance

Collision avoidance systems typically have put transducers on the rearof the vehicle and measure the distance from the sensor to the object.This is not optimal since those sensors are transmitting in an arc. Theyare looking at the distance from the sensor to the object and backagain. That may not, however, be the perpendicular distance from thevehicle to the object. A deficiency, therefore, of such systems is thatthey do not communicate to the driver the transverse location of thisobject.

In one embodiment of the system shown in FIGS. 1 and 2, a plurality ofsensors 14 are mounted on the back of the vehicle. Control module 12takes the readings from the rear-mounted sensors 14, determines whetherit can triangulate and calculates an actual perpendicular distance fromthe truck to the object. This is important because the truck driverreally wants to know, not that the object is off at this angle over herefive feet away, is how far he can back up before he hits the object. Incontrast to other approaches, this triangulation procedure makes systems10 and 30 precision distance measuring systems.

FIG. 5 a represents the top view of a tractor trailer rig 50 with a post52 located behind the trailer 54. The post 50 represents a hazard unlessthe driver knows the precise distance from the vehicle. Sensor 14 on theright rear of the trailer senses the post 52 at a distance of six (6)feet. Sensor 14 on the left rear of the trailer senses the post at adistance of just over six and one half (6.5) feet. Control System 12calculates that the actual distance to the post as 5.2 feet anddetermines it is located just to the right of the center of the trailer.The distance is then displayed digitally on the control module 12. Thetransverse location is displayed, for instance, on the bar graph locatedjust to the right of the digital display and it indicates the locationof the post.

Perpendicular distance between the rear of a vehicle and externalobjects is increasingly important the closer the vehicle gets to anexternal object. In the same example as above, when sensor 14 on theright rear of the trailer senses the post at a distance of four (4) feetand the sensor 14 on the left rear senses the post at a distance of 4.8feet, the actual perpendicular distance is 2.6 feet. The PrecisionMeasurement System described in U.S. patent application Ser. No.09/130,279, the description of which is hereby incorporated byreference, correctly uses the sensor 14 distance readings as well as theknown distance between the left and right sensors 14 to calculate theexact perpendicular distance to the post. This is very important as anaid to the driver in the prevention of an accident.

In one embodiment, a third sensor 14 is mounted between the right andleft sensors 14. With the aid of third sensor 14, the system candetermine that the object is a point source (such as a post) as opposedto a wall or large vehicle. The sensor 14 on the right rear of thetrailer senses the post at a distance of six (6) feet. The sensor 14 onthe left rear of the trailer senses the post at a distance of just oversix and one half (6.6) feet. Control module 12, knowing that the objectis a point source, calculates that the actual distance to the post is5.2 feet and is located just to the right of the center of the trailer.The distance is displayed digitally on the Operator Interface and SideDisplay Modules. The transverse location is displayed in graphic form(e.g. bar graph) on the Operator Interface. One such embodiment isdescribed in U.S. patent application Ser. No. 09/130,279, thedescription of which is hereby incorporated by reference.

FIG. 5 b represents the top view of a tractor trailer with a postlocated far behind the trailer. The post represents a hazard unless thedriver has sufficient information to aid in maneuvering around theobstacle. The sensor 14 on the right rear of the trailer senses the postat a distance of 21.0 feet. The sensor 14 on the left rear of thetrailer senses the post at a distance of 22.1 feet. The control module12 calculates that the actual distance to the post is 21.0 feet, andthat it is located near the right side of the trailer. The distance isdisplayed digitally on the operator interface. The transverse locationis displayed on the bar graph located just to the right of the digitaldisplay and it indicates the location. Precision distance measurement isless of a concern when obstacles are a long distance from the rear ofthe vehicle. However, productivity is a concern. With the aid of thetransverse location information and the ability of the control module 12to detect objects up to 25 feet behind the vehicle, the driver of thetractor trailer shown in FIG. 5 b can readily maneuver the vehicle toavoid the obstacle without having to stop, drive forward, and thenproceed in backing the vehicle.

In order to triangulate, the distance between sensors 14 must be known.Therefore, the distance between sensors 14 must be controlled. In oneembodiment, the distance between sensors 14 is a system parameter thatcan be programmed. In one such programmable embodiment, a programmingdevice is provided to a dealer or a fleet owner such that once sensors14 are installed, they can measure the actual distance between thesensors and the distance from the sensors to the sides of the vehicleand program that into control module 12. Control module 12 can thenaccurately calculate distance.

For example, if a collision avoidance system 10 or 20 provides ameasurement, is that object directly behind the vehicle, or is it off tothe left or right? Is it actually far enough off to the left or farenough off to the right that he won't hit it but needs to be aware ofit? To provide more accurate information, in one embodiment, controlmodule 12 calculates transverse location and communicates thatinformation via a graphical indicator. Such an approach is shown inFIGS. 6 a-6 c and is described in U.S. patent application Ser. No.09/130,279 filed Aug. 6, 1998, the description of which is herebyincorporated by reference.

Another issue is the vertical position of the rear-mounted transducers,relative to the ground, and relative to the impact point with a loadingdock, is an important issue. For example, loading docks have an impactplank that protrudes out from the wall. If sensors 14 are mounted toolow, you may actually look underneath the impact plank. If so, the truckcould hit the plank under power with the driver thinking he or she hadanother 4-6 inches to go. In one embodiment, system 10 includes verticalcompensation as discussed below.

In one embodiment, vertical compensation is activated automatically viaa front panel switch mounted in a front panel module 60 such as is shownin FIGS. 6 a-6 c. The purpose of this feature is to compensate for theprotrusion of loading dock impact pads in cases where sensors 14 arelocated below the point of impact of the trailer with the loading dockimpact pad.

FIG. 5 c represents the side view of a tractor-trailer pulling up to aloading dock. The impact pad is the point of contact with the trailer.The depth (i.e., front-to-back) of the impact pad is typically 4.5inches. The top of the impact pad is typically 48 inches above theground. In one embodiment, when the sensors 14 are located below thepoint of impact of the trailer with the impact pad, the systems 10 and30 adjust the distance measurement by 4.5 inches if the TransducerAssembly is mounted so low that it cannot detect the impact pad when thetrailer is within 12 inches of the impact pad. For example, if theperpendicular distance from the rear of the trailer to the loading dockis 1 foot and the Transducer is 2 feet below the impact bar, themeasured distance of 1.0 feet will be corrected to 0.6 feet.

In one embodiment of systems 10 and 30, a backup warning system isprovided as shown in FIG. 7. In one such embodiment, sensors 14 includetransducers placed on the rear of the vehicle. Those transducers areactivated when the driver shifts his transmission into reverse. As soonas the driver shifts into reverse, the transducers on the back begin tosend out sound energy from the transducers, which bounces off an object,comes back to a receive transducer. Distance is then calculated as afunction of time of return (e.g., acoustic applications) or intensity ofthe return signal (e.g., radar applications). In one embodiment, aMultiple Hypothesis Ranging algorithm is used to calculate distance.Such an algorithm is described in U.S. patent application Ser. No.09/130,279 filed Aug. 6, 1998, the description of which is herebyincorporated by reference.

In addition, in one embodiment, when sensors 14 detect that there'ssomething back there, systems 10 and 30 alert the driver immediately(e.g., by flashing 44, 46 or 48), so that he or she can take action andnot back into whatever object is being detected.

The intent is to provide immediate feedback to the driver shortly afterthe vehicle transmission is shifted into reverse. This informationincludes information on objects in the vicinity of the rear of thevehicle as well as information on objects in the path of the rear of thevehicle. In one embodiment, in the case where objects are in closeproximity to the rear of the vehicle, but not in the path of thevehicle, an auditory prompt representing an “alert” is sounded for thedriver. (This is in addition to lighting the appropriate LEDs in mirrors40 and 41.) If an object is detected in the path of the vehicle, in therange of 5 to 10 feet, the system will categorize that as a hazardsituation and an auditory prompt representing a “warning” is sounded forthe driver. If an object is detected in the path of the vehicle, withina range of 5 feet, the system will categorize that as an emergencysituation and an auditory prompt representing an “emergency” is soundedfor the driver. After the vehicle has been backing up for two or moreseconds, the alert, warning, and emergency will have cleared and thesystem will begin providing range feedback to the driver in the form ofdistance information, as displayed on the Operator Interface and SideDisplay Modules, and auditory feedback in the form of pulsed tones. Thecloser the vehicle gets to an object, the faster the repetition rate ofthe pulses until the rear of the vehicle is within one foot at whichtime the pulses have turned into a continuous tone. In the process ofbacking up, if a person or vehicle suddenly appeared behind the vehicle,the system will automatically detect a sudden change in range to theobject and the “emergency” auditory prompt will be issued to the driverso he/she can take action.

In one such embodiment, when the driver is going to back up, if there isan object within range, one of three scenarios will happen. First, ifthe system senses a truck or other object close to the truck on eitherside, systems 10 and 30 will give him an alert. The system knows thatthere is no collision potential here, but just alerts him that there issomething there. In one embodiment systems 10 and 30 provide one set oftones to the driver for an alert. Second, if there is an object in therange of 5-10 feet as soon as the driver throws it into reverse, systems10 and 30 sense the object and provide the driver with a different alarm(e.g., a different set of tones or a different flashing light). Thisalarm is called a hazard alarm. And again, that's to alert the driver sohe can take action on the hazard alarm. Third, if there is an objectwithin 5 feet, the driver receives an emergency alarm (i.e., a third setof tones, or a third flashing light). Systems 10 and 30 thereforeprovide feedback indicative of the distance to an object behind thedriver. In one such embodiment, audible or visual feedback tells thedriver he's getting closer; the pulses go faster and faster to the pointwhere, when he's within a foot, the pulses are continuous. But, if inthe process of backing up, the system automatically detects that thedistance suddenly became shorter, it will provide the emergency alarmright away so the driver can take action. For example, if somebody drovein behind the driver, or some kid ran in back of the vehicle, systems 10and 30 sense that and automatically provide the emergency alarm so thedriver can take action. As noted above, some of the systems that are outthere actually detect zones of distance and provide feedback for that.Systems 10 and 30 go beyond that in that they detect and differentiateobjects outside the area of potential collision from those inside andsecondly, they can detect sudden changes in distance for an emergencyalarm.

In one embodiment, the side view mirrors of FIGS. 4 a and 4 b displayinformation corresponding to the zones. In that embodiment, detectionthat the truck is in emergency zone 70 causes rapid flashing of LEDs 1-4and triangle 48 to alert the driver of the proximity of the object. Inaddition, in one embodiment hazard zone 72 is divided into four zonescorresponding to each of LEDs 1-4 as described above.

In one embodiment a self test capability is provided. Self testaddresses several issues. One is when systems 10 and 30 are first turnedon (i.e., the driver throws the power switch into an “on” position) thesystems will turn all the indicators on so that the driver right awaycan see that all the indicators are lit. In addition, control module 12tests its internal circuitry to ensure that the system comes up running.The second thing the system does is while it's running, if the microcontroller or microprocessor in control module 12 were to fail, systems10 and 30 then provide a “watch-dog timer” that will detect the failure.Thirdly, the driver can activate self test mode. On doing so, in oneembodiment, control module 12 flashes all of the indicators of frontpanel 20 and/or of mirrors 40 and 41. In one such embodiment, controlpanel 20 includes an indicator 24 for each transducer mounted around thevehicle and, on entering self test, transducer indicators 24 begin toflash. The driver then walks around the vehicle and gets back in thecab. Every one of those transducers should detect him; each time theydetect him, the transducer indicator 24 associated with the transducergoes off (i.e., quits flashing). If the driver gets back to the cab andthere's a transducer still flashing, he knows that something didn't workand he can investigate the problem.

Wireless Portable Transducer System

In one embodiment sensors 14 are provided within a wireless portabletransducer system 40. The problem with wired transducer systems is that,if you look at the number of trailers out there, they far exceed thenumber of truck-tractors out there. And so truck-tractors are basicallymoving from trailer to trailer. It could easily reach the point whereestablishing a complete collision avoidance system 10 or 30 on eachcombination of tractors and trail would be prohibitively expensive. Tobetter address the needs of fleet owners, a system 10 is constructedhaving a wireless portable system 40. FIGS. 8 and 9 show two embodimentsof such portable systems.

In FIG. 8, two boxes 70 provide the portable transducer function. Eachbox 70 includes an antenna sticking out the side. Each box 70 mountsunder the trailer and clamps to the frame of the trailer. Inside eachbox 70 is an ultrasonic transmitter and receiver, electronic circuitry,and a radio transmitter and receiver. A two wire cable connects batteryfrom the trailer to the electronic circuitry to provide power. A cablebetween each box provides common control signals from the radiotransmitter/receiver such that signals from either rear mounted antennacontrol both Transducer Assemblies.

In FIG. 9, there is one long extrusion with an antenna sticking out eachside. The extrusion clamps to the frame on the rear of the trailer. Theextrusion may be made of one piece, or two pieces (one within another)with a mechanism to adjust the width of the extrusion to the width ofthe trailer. A Transducer Assembly (transmitter and receiver) is mountedon each end of the extrusion. The electronic circuitry, including radiotransmitter and receiver are mounted inside the extrusion. In oneembodiment, a two wire cable connects battery from the trailer toprovide power to the electronic circuitry.

Signals to and from the boxes 70 are communicated to the control moduleof the collision avoidance system via the Wireless Communicator todetect, measure, and display distance to objects behind the trailer.

System 40 is designed so that it can quickly be disconnected from onetrailer and moved to another trailer.

In one such embodiment, a Wireless Portable Transducer System providesfor wireless communication between the electronics mounted in the cab ofthe vehicle and the Portable Transducer Array mounted on the rear of thetrailer. Power to operate the Portable Transducer Array is provided byconnecting in to existing power wiring provided to the trailer from thetruck's electrical system.

Dependent on the transducer technology used, the Portable TransducerArray could be made to be totally battery operated. For example, if thePortable Transducer Array were designed using Micropower Impulse Radar,Doppler Radar or other alternative low-power technologies, thetransmitting and receiving functions to measure distance to objectsbehind the vehicle would be low power and could operate on batteriesbuilt into the Portable Transducer Array. The communications between theelectronics in the cab of the vehicle and the Portable Transducer Arraycould also use Micropower Impulse Radar, Doppler Radar, or otheralternative low-power technologies, thus enabling portability withbuilt-in battery power. This solution will eliminate the need to tapinto the truck's electrical system to power the Portable TransducerArray.

Wireless embodiments of collision avoidance systems are described inU.S. patent application Ser. No. 09/130,279, filed Aug. 6, 1998, thedescriptions of which are hereby incorporated by reference.

In one embodiment, the bulk of the electronics stays with the tractor.In addition, the rear transducer array stays with the tractor (i.e., asthe driver goes from trailer to trailer he simply pulls off system 40and clamps it on the next trailer. In one such embodiment, a connectorarrangement is provided so the driver can connect system to the powerthat's already on the trailer and quickly get the system up and running.

In another embodiment, multiple sensors are designed into the wirelesssubsystem 40 to detect obstacles to the rear of the vehicle and oneither side of the vehicle. Communication with control module 12 is viawireless digital signals. Control module 12 is designed to sense whenthe wireless portable sensor subsystem is not installed or is notfunctioning properly.

Different quick-connect mounting arrangements might be needed fordifferent style trucks. In one embodiment, as is shown in FIG. 9,portable wireless sensor subsystem 40 is a tubular structure withintegral electronics, battery pack, and sensors mounted internal orexternal to the structure. The unit would clamp on the trailer chassisor the underride bumper provided on the rear of many trailers. Antennaswould be mounted on one or both sides of the wireless portable sensorsubsystem protruding just outside the left and right edges of thetrailer. In another embodiment, as is shown in FIG. 8, portable wirelesssensor subsystem 40 is enclosed in two separate housings mounted at theleft rear or right rear of the trailer. Again, quick connect mountingarrangements will be made to secure each unit to the trailer. A cablewill interconnect each unit to allow the sharing of one battery pack,one controller, and one wireless transceiver.

In another embodiment of system 40, the sensors on the trailer arehardwired together. Communication between the sensors and control module12, however, is wireless. In this case, a Transceiver Module is mountedon the tractor and a second unit on the trailer. The Transceiver Moduleon the trailer receives its power from the tractor-trailer umbilicalelectrical cable. Electrical signals are passed between tractor andtrailer just like any non-wireless system with the exception that thesignals are converted to wireless communication and then reconvertedback to their electrical form at the other end. This approach providesadditional flexibility for the customer's needs.

In one embodiment of system 30, systems may be equipped with a SideDisplay Module, such as is shown in FIG. 10. Side Display Module 35 ismounted internal or adjacent to each side view mirror. If one or moresensors 14 on the side of the cab detect an object, Side Display Module35 will flash a forward-directed arrow on that side of the vehicle. Inone embodiment, if one or more sensors on the side of the trailer detectan object, Side Display Module 35 flashes a rear-directed arrow on thatside of the vehicle. If objects are detected on both the side of the caband the side of the trailer, Side Display Module 35 flashes an arrowpointed both forward and to the rear. In one such embodiment, SideDisplay Module 35 also displays the distance between the rear of thevehicle and any object behind the vehicle when the transmission is inreverse.

In one embodiment, as is shown in FIG. 10, side display module 35provides visual feedback to the driver when looking in the direction ofeither side view mirror. These modules 35 may be mounted on the edge ofthe side view mirrors, or they may be mounted inside the cab in theapproximate line-of-sight as the side view mirrors.

In one embodiment, display modules 35 include a plastic housing, a smallPCB Assembly with five LED indicators, two half-inch high seven segmentdisplays, a cable which runs into the cab and connects to the rear ofthe Control module, and a clear plastic cover on the front of themodule. The display module 35 mounted on the left side of the cab isidentical to the module mounted on the right side of the cab. Displaymodule 35 can be used in addition to the displays in side view mirrors40 and 41.

In one embodiment, the seven-segment display drivers and LED driver arelocated in the Control module. The display shown in FIG. 10 shows adistance reading of twelve feet (12′). In one embodiment, distancereadings associated with the Forward-Looking Detector Subsystem are notdisplayed on Side Display Modules 35. Only Backup Mode rear distancereadings are displayed. If an alarm condition exists anywhere around thevehicle, all five LED's flash. The LEDs are not meant to provide anydetector-specific information. Similarly, in one embodiment, thegraphics displays shown in FIGS. 6 a-c and/or the displays in mirrors 40and 41 flash a visual warning on detection of an alarm condition.

A collision avoidance system 100 for vehicles such as school buses willbe described next. In one embodiment, as is shown in FIG. 11, system 100includes a front sensor 102, two or more side sensors 104 and a rearsensor 106.

In one embodiment, system 100 mounts on and monitors the front, sides,and rear of a school bus. Unlike the standard collision avoidance systemfor which front and side sensors are intended to provide collisionwarning when the vehicle is above a certain speed, in one embodiment,system 100 activates front and side sensors (102, 104) when the bus isbelow a certain speed (starting or stopping). The primary intent ofsystem 100 is to warn the driver of objects and pedestrians in closeproximity to the bus.

In one embodiment, system 100 consists of multiple sensors and optionaldriver interface units (both visual and audible). If the optional driverinterface units are not used, driver interface information is passed toan integrated vehicle driver information system via an SAE J1708 or SAEJ1939 serial data link. In one embodiment, sensor arrays 102, 104 and106 are stand-alone in that the sensor data processing required forvalid object detection takes place on the sensors without the need (andcost) of a centralized computer.

In one embodiment, sensors consist of a combination of radar-based units(Type A and Type B) and ultrasonic-based units (Type U). The Type Asensor drives both the Type B and Type U sensors in a master/slavearrangement, providing the most cost-effective configuration formultiple sensor applications.

In one such embodiment, the sensors operate from 12 VDC vehicle batterypower, with protection circuits to protect the electronics from (1)surges due to an overcharging alternator, (2) reverse voltage, or (3)electrostatic discharge.

In one embodiment, all sensor housings effectively seal against allenvironmental conditions, solvents, and sprays encountered on theexterior of a vehicle per SAE J1455. All sensors are certified to complywith SAE J1455 and with FCC requirements.

In one embodiment, all sensor housings are connectorized. Optionalcables and harnesses designed to withstand the environmental conditionscalled out in SAE J1455 are available. Connectors utilize a lockingmechanism, are environmentally sealed, and provide highly reliableelectrical connections under continuous shock and vibration.

In one embodiment, sensor configurations provide a built-in-testfunction that detects a malfunction in any of the sensors and passesthis information on to the driver interface.

In one embodiment, the Type A Sensor is a stand-alone radar sensor. Inaddition to processing it's own radar data, it processes radar data fromup to 2 Type B sensors and ultrasonic data from up to 3 Type U sensors.The Type A sensor can be programmed during installation to indicate itsposition on the bus, as well as the position of any Type B or Type Usensors connected to it. Driver alert thresholds (sensitivity) are alsofield programmable. Standard configurations (position and sensitivity)are available, so programming is not required during installation.

In one embodiment, vehicle information (speed, reverse, stop flashers)is provided to the Type A sensor either directly, via a direct link to aradar sensor configured to sense speed and to the reverse switch andflasher switch, or indirectly, via the J1708 or J1939 interface on theVehicle/Driver Interface (VDI) unit.

In one embodiment, the Type A Sensor can detect an object the size of asmall child at up to 25 feet, with a ±45° beamwidth. The sensor can beturned off or the range limited based on its position on the vehicle andthe vehicle status. The sensor can be programmed to detect objects thatare moving at a speed of 0.2 to 10 mph relative to the vehicle, and todifferentiate between stationary and moving objects.

In one embodiment, valid detection of an object is reported to thedriver interface within 400 ms of when the object meets the detectioncriteria. A sudden change in range for objects with a radar view equalto or larger than a small child (30″ tall) within 10′ of the vehicle, isreported to the driver interface within 200 ms of occurrence.

In one embodiment, front sensors 102 and side sensors 104 are activatedwhen the speed drops below 5 mph and stop flashers are turned on. Frontsensors 102 and side sensors 104 remain active until the engine isturned off or vehicle speed moves above 10 mph. In one embodiment, rearsensors 106 are active whenever the transmission is in reverse.

In one embodiment, the Type A sensor provides alarm type and alarmon/off messages to the VDI unit based on its own radar data and radarand ultrasonic data from any attached slave units. For alarms based onfront sensor data, once an object is detected and an alarm conditionpresented to the driver, the alarm remains on until the object isremoved from the front of the vehicle. For alarms based on side sensordata, once an object is detected and an alarm condition presented to thedriver, the alarm remains on until the object is removed from the sideof the vehicle, or the vehicle speed exceeds 10 mph. For alarms based onrear sensor data, once an object is detected and an alarm or rangecondition is presented to the driver, the alarm remains on, or the rangecontinues to be presented, until the object is removed from the rear ofthe vehicle, or the transmission is shifted out of reverse. All alarmsare extinguished within 1 second of when the alarm clearing eventoccurs.

The Type B Sensor is identical to the Type A in functionality andperformance with the exception that the Type B is a slave to the Type Aand the Type A does the radar data processing for the Type B.

The Type U Sensor is an ultrasonic sensor that is slaved to a Type Aradar sensor. The Type U sensor is primarily intended for use on therear of a vehicle, where accurate range information is valuable toassist the driver while backing the vehicle. Type U sensors are alwaysused in conjunction with radar sensors so that if environmentalconditions exists which impair the performance of the ultrasonic sensor(heavy dirt or ice coating, very strong wind, or very heavy rain orsnow), radar data can automatically be substituted for the ultrasonicdata. When this automatic substitution takes place, an indication thatthe ultrasonic sensor is impaired is provided to the driver interface.

In one embodiment, the Type U sensor measures the range to any objectequal to or larger than a 1″ diameter pipe 3′ long at a range of 6″ to12′ behind the truck with an accuracy of +/−10% or +/−2″ (whichever isgreater). The range measurement tracks actual range within specificationfor vehicle speeds up to 5 mph. The range measurement tracks actualrange with an accuracy of +/−20% for vehicle speeds of 5 mph to 15 mph.

In one embodiment, the Vehicle/Driver Interface (VDI) unit provides aninterface between the sensor array and both the vehicle and the driver.The VDI unit reads vehicle information (speed, reverse, stop flashers)from the J1708 or J1939 data links on the vehicle and provides thisinformation to the Type A sensors. The VDI unit also relays driverinterface information from the Type A sensors to the J1708 or J1939 datalinks on the vehicle for use on vehicle-integrated driver interfacesystems. The VDI unit will drive up to two LED displays (e.g., mirrors40 and 41) and one audio unit.

In one embodiment, the VDI unit operates from 12 VDC vehicle batterypower, with protection circuits to protect the electronics from (1)surges due to an overcharging alternator, (2) reverse voltage, or (3)electrostatic discharge.

In one embodiment, the VDI unit housing effectively seals against allenvironmental conditions, solvents, and sprays encountered on theexterior of a vehicle per SAE J1455. In one such embodiment, the VDIunit is certified to comply with SAE J1455 and with FCC requirements.

In one embodiment, the VDI unit is connectorized. Optional cables andharnesses designed to withstand the environmental conditions called outin SAE J1455 are available. Connectors utilize a locking mechanism, areenvironmentally sealed, and provide highly reliable electricalconnections under continuous shock and vibration.

In one embodiment, the VDI unit provides a built-in-test function thatdetects a malfunction in itself or any of the optional driver interfaceunits and passes this information on to the driver interface.

In one embodiment, stand-alone driver interface units (DIUs) include LEDdisplays, digital readouts (future), and audible feedback units. Theseunits provide flexible stand-alone configurations that result in highreliability and minimized cost.

In one embodiment, DIUs operate from power provided by the VDI unit. DIUhousings intended for mounting on the exterior of the vehicle,effectively seal against all environmental conditions, solvents, andsprays encountered on the exterior of a vehicle per SAE J1455. In onesuch embodiment, DIUs are certified to comply with SAE J1455 and withFCC requirements.

In one embodiment, all DIU housings are connectorized (either directlyor through a pre-attached connectorized cable). Optional cables andharnesses designed to withstand the environmental conditions called outin SAE J1455 are available. Connectors utilize a locking mechanism, areenvironmentally sealed, and provide highly reliable electricalconnections under continuous shock and vibration.

In one embodiment, each DIU provides a built-in-test function thatdisplays malfunctions detected in any of the sensors and passes thisinformation on to the driver interface. All DIUs provide positivefeedback to the driver that shows that they are fully functional everytime the system is powered up. This includes lighting all displaysegments and exercising the audio unit in a pleasant distinctive manner.In one embodiment, if the power-up BIT functions detect a systemfailure, the audio unit is exercised in a less pleasant distinctivemanner.

In one embodiment, a mirror-mount LED display (MLD) 110 provides visualfeedback to the driver. In one embodiment, as is shown in FIG. 12, MLD110 includes six LEDs (112.1 through 112.6) mounted vertically in a row,and intended to be mounted on the outside of each side mirror. MLD 110is designed for viewing in a wide range of weather and lightingconditions. It can also be mounted inside the bus, on an A bar or on thedash. From the top, the LED functions are: LED 112.1 lights amber forsystem status, LED 112.2 lights red for side and front sensors, LEDs112.3-5 light amber and LED 112.6 lights red, all for rear sensor 106.In one embodiment, spacing between the top 3 LEDs (LED 112.1-3) isslightly wider than the spacing between the bottom 4 LEDs (LED 112.3-6).

In one embodiment, LEDs 112 are mounted on a printed circuit board 114and protected with a translucent top housing and an opaque bottomhousing. Wire termination holes 116 are provided at the bottom of PCB114. In one embodiment, PCB 114 is designed to draw heat away from LEDs112.

In one embodiment, LED 112.1 is a system status indicator. In the normalstate (no malfunctions) it turns on and off providing a 0.5 Hz heartbeat(75% duty cycle, off 250 ms, on 250 ms, off 250 ms, on 1250 ms). Forabnormal conditions, LED 112.1 flashes at a 4 Hz rate for 1 minute atpower-up and again for 1 minute at any time that an attempt is made toactivate the failed circuitry, and remains off the rest of the time. Itsimply remains off all of the time for certain failure conditions thatprevent LED 112.1 from flashing. A special abnormal condition is whenthe system detects that the ultrasonic sensors are not functioningcorrectly and range is coming from the radar sensors. In this casestatus light 112.1 flashes at 4 Hz for 1 second and then off for 1second. This continues as long as there are objects detected by theradar sensors that should be picked up by the ultrasonic sensors, butare not.

LED 112.2 is a side and front object detection indicator. Left and rightMLDs 110 are driven independently. For side object detection, LED 112.2on MLD 110 on the side on which the object is detected flashes toindicate the detection. Ranges and flashing patterns can be customized,but the default is 1 Hz flashing for an object 4 to 8 ft from the busand 4 Hz flashing for an object 0 to 4 ft from the bus. For front objectdetection, the performance is the same, but both left and right MLDs 110flash in unison. If a single MLD 110 is used, LED 112.2 indicates thatan object has been detected on the front or on either side. When inreverse, LED 112.2 can be used to indicate side object detection at alimited range. The default settings, when in reverse, are 2 to 4 ft for1 Hz flashing and 0 to 2 ft for 4 Hz flashing.

Remaining LEDs 112.3-6 are rear range indicators. LEDs 112.3-5, alongwith LED 112.6, indicate the range to the nearest object detected to therear of the bus when the bus is in reverse. The default pattern for rearrange indication is as follows (where A1, A2 and A3 indicate LEDs 112.3,4 and 5, respectively): 10′ to 20′ A1, A2, A3, and red flashing at 2 Hz5′ to 10′ A2, A3, and red flashing at 2 Hz 2′ to 5′ A3, and red flashingat 2 Hz 6″ to 2′ red flashing at 2 Hz ≦6″ all 6 lights flashing at 4 Hz

A sudden change in range, indicating that a moving object (child,bicycle, or vehicle) has suddenly moved into the path of the backingbus, will also result in all 6 lights flashing at 4 Hz.

In one embodiment, a side-mount LED display (SLD) 120 is used instead ofMLD 110 to provide visual feedback to the driver. In one embodiment, asis shown in FIG. 13, SLD 120 includes six LED marker lights (LEDs 122.1through 122.6) mounted vertically in a row, and intended to be mountedon the outside surface of the bus within the sight line of each sidemirror. SLD 110 is designed for viewing in a wide range of weather andlighting conditions. It also can be mounted inside the bus, on an A baror on the dash. From the top, the LED functions are: LED 122.1 lightsamber for system status, LED 122.2 lights red for side and frontsensors, LEDs 122.3-5 light amber and LED 122.6 lights red, all for rearsensor 106. In one embodiment, spacing between the top 3 LEDs (LED112.1-3) is slightly wider than the spacing between the bottom 4 LEDs(LED 112.3-6).

In one embodiment, SLD 120 operates in a manner similar to MLD 110described above.

In one embodiment, LED marker lights 122 are mounted within an aluminumframe 124. Spacers 126 are situated as needed within frame 124. A sideview of frame 124 (in FIG. 14) shows holes 128 for screwing frame 124 tothe side of the vehicle.

In one embodiment, a Dash-Mount Audio Unit (DAU) provides audiblefeedback to the driver. The DAU housing is designed to fit into astandard circular knockout on the dashboard. It includes a single greenLED to indicate that it is connected and getting power from the VDIunit. The DAU provides tones of varying pulse rate and pulse length toindicate the various alarms and range indications. The DAU is designedto be heard in the noisy environment of a school bus.

In one embodiment, the pulse patterns can be customized, but the defaultpatterns are as follows: Left side detection at 4 to 8 ft Long/short 1Hz pattern Left side detection at 0 to 4 ft Long/short 2 Hz patternRight side detection at 4 to 8 ft Short/long 1 Hz pattern Right sidedetection at 0 to 4 ft Short/long 2 Hz pattern Front detection at 4 to 8ft 3 short pulses, 1 Hz pattern Front detection at 0 to 4 ft 3 shortpulses, 2 Hz pattern Rear detection at 10 to 20 ft 0.5 Hz 25% duty cyclepattern Rear detection at 5 to 10 ft 1 Hz 50% duty cycle pattern Reardetection at 2 to 5 ft 2 Hz 50% duty cycle pattern Rear detection at 0.5to 2 ft 4 Hz 50% duty cycle pattern Rear detection at <0.5 ft steadytone

In one embodiment, rear audible alerts continue as long as the bus is inreverse. Front and side audible alerts can be programmed to extinguishafter a fixed period (eg., 4 seconds), while the visual alert continues,if conditions remain static. The audible alert restarts if conditionschange (i.e., more movement than that provided by a parked car with itsengine running).

In one embodiment, a system malfunction is indicated with an audiblealert that consists of a continuous 4 pulses per second, lasting for 4seconds. This occurs on power up and when the malfunction is firstdetected only. Detection of an ultrasonic sensor with degradedperformance is indicated by an audible alert that consists of 4 pulsesthen 1 second rest, in sync with the status LED, repeated 2 times,whenever an object is picked up by the radar sensors that the ultrasonicsensor is missing.

In the above discussion, the term “computer” is defined to include anydigital or analog data processing unit. Examples include any personalcomputer, workstation, set top box, mainframe, server, supercomputer,laptop or personal digital assistant capable of embodying the inventionsdescribed herein.

Examples of articles comprising computer readable media are floppydisks, hard drives, CD-ROM or DVD media or any other read-write orread-only memory device.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiments shown. This application isintended to cover any adaptations or variations of the presentinvention. Therefore, it is intended that this invention be limited onlyby the claims and the equivalents thereof.

1. A collision avoidance system for a vehicle, comprising: one or moretransmitting devices; one or more receiving devices, wherein thereceiving devices receive return signals; a control module connected tothe transmitting devices and the receiving devices, wherein the controlmodule detects a hazard based on information on the return signalsreceived from the one or more receiving devices; and a mirror, whereinthe mirror includes visual indicators for warning a driver of the hazarddetected by the control module.